With the continuing evolution and development of communications technologies, the IP multimedia subsystem (IP Multimedia Subsystem; hereinafter referred to as TMS) network has gradually developed into a core network architecture of the 3rd generation partnership project (3rd Generation Partnership Project; hereinafter referred to as 3GPP), and coexists with a circuit switching (Circuit Switching; hereinafter referred to as CS) network in a long term, so as to provide an IP multimedia service for a fixed and mobile subscribers that gets access with packets. The emergence of the IMS centralized services (IMS Centralized Service; hereinafter referred to as ICS) enables various services to be consistently controlled by an IMS network, so as to implement seamless and efficient interworking among various access ways.
In an ICS architecture, a mobile switching center (Mobile Switching Center; hereinafter referred to as MSC) evolves into a mobile access gateway control function (mobile Access Gateway Control Function; hereinafter referred to as mAGCF); and a supported protocol is converted from the 3GPP 24.008 protocol to the session initiation protocol (Session Initiation Protocol; hereinafter referred to as SIP). Accordingly, an MSC POOL (POOL) may evolve into a mAGCF POOL. The current 3GPP protocol does not definite a processing procedure of a mAGCF POOL, so a disaster recovery processing procedure of the mAGCF POOL under the ICS architecture in the prior art uses the one that is similar to a disaster recovery processing procedure of the MSC POOL. During an existing disaster recovery processing procedure in a mAGCF POOL, when a subscriber terminal is located at an IMS domain as a called party, and a primary mAGCF has a failure, an application server (Application Server; hereinafter referred to as AS) is required to send an SRI (MAP_SEND_ROUTING_INFORMATION) message which carries a mobile station international integrated service digital network (Integrated Service Digital Network; hereinafter referred to as ISDN) number (Mobile Station International ISDN Number; hereinafter referred to as MSISDN) to a home location register (Home Location Register; hereinafter, HLR). Then the HLR sends a PRN (PRN MAP_PROVIDE_ROAMING_NUMBER) message to the mAGCF, so as to acquire a mobile station roaming number (Mobile Station Roaming Number; hereinafter, MSRN) that is allocated to the mAGCF, and to trigger a connecting to a called terminal through the MSRN when the mAGCF has a failure.
During a disaster processing procedure in a mAGCF POOL, whether a called terminal is located at a CS domain or at an IMS domain, an AS may unconditionally acquire an MSRN from the CS domain, and the mAGCF is required to provide an MSRN for a subscriber in the IMS domain, and as a result, the performance of both the AS and the mAGCF is degraded; meanwhile, routing data of the MSRN is required to be configured, and as a result, a large number of routing resources are wasted.